Question

Alright, so I’m back with another question. I know in Python there is a way to read in a file without specifying which file it will be, until you are in the command prompt. So basically you can set the script up so that you can read in any file you want and don’t have to go back and change the coding every time. Is there a way to do this in Perl? If so, can you write files like that too? Thanks.

This is what I have:

open (LOGFILE, "UNSUCCESSFULOUTPUT.txt") or die "Can't find file";       
open FILE, ">", "output.txt" or die $!;

while(<LOGFILE>){
print FILE "ERROR in line $.\n" if (/Error/);
}






close FILE;
close LOGFILE;                  

This is what I have nome:

#!/usr/local/bin/perl


my $argument1 = $ARGV[0];
open (LOGFILE, "<$argument1") or die "Can't find file";     

open FILE, ">>output.txt" or die $!;


while(<LOGFILE>){
print FILE "ERROR in line $.\n" if (/Error/);
}





close FILE;
close LOGFILE;

And it’s still not appending…

Answer 1

This is what I believe you want:

#!usr/bin/perl
my $argument1 = $ARGV[0];

open (LOGFILE, "<$argument1") or die "Can't find file";       
open (FILE, ">output.txt") or die $!;

while(<LOGFILE>){
print FILE "ERROR in line $.\n" if (/Error/);
}

close FILE;
close LOGFILE; 

Ran as from the command line:

> perl nameofpl.pl mytxt.txt

For appending change this line:

 open (FILE, ">output.txt") or die $!;

To the remarkably similar:

 open (FILE, ">>output.txt") or die $!;